Technical information about Timing belts

Depending on the application of the product, choose the cables or material to be used.

It is considered that in power transmission, it is necessary to turn quickly on small pulleys, at constant speed. In transport, products are transported on the back of the belt.
The stresses on the belt are therefore different.

Power transmission
Poly Chain® power transmission belts have been designed for high torque and low speed transmissions. The reinforcement of these carbon fiber belts provides dimensional stability, which ensures perfect belt springs on the pulley.

Synchronous polyurethane belts provide excellent mechanical resistance to the tooth as well as a very good resistance to abrasion. The best thermal resistance of the power transmission belts is the polyurethane Poly Chain belt which can withstand -54 ° C to 140 ° C against only -20 ° C to 100 ° C for a Neoprene transmission belt. The neoprene transmission belt offers a very high resistance to fatigue (neoprene being a more flexible material than the PU).

The abrasion resistance of a Neoprene belt will be more average compared to a polyurethane belt.

The specific construction of synchronous belts in Polyurethane offers superb resistance to oils, acids and chlorine. The most fire resistant is Poly Chain®.

Transport
The conveyor belt offers the same technical characteristics as a Polyurethane belt (sleeve).

Cables for timing belt
The comparison of the different cables in the toothed belts shows some characteristics. There are 4 types of cables in transmission belts that are: Fiberglass - Steel – Kevlar® or Aramid and Carbon. The steel cords offer excellent tensile strength and provide very small elongation and more flexibility than fiberglass cables.

Fiberglass cables are characterized by excellent resistance to fatigue and very good resistance to moisture; such as the carbon traction cord.

YOUR QUESTIONS ABOUT TIMING BELTS

When should I use KEVLAR® instead of steel?
There are several considerations that can affect the choice of KEVLAR® vs. steel:
1- Use of a metal detector around the belt
2- Most food applications prefer KEVLAR® vs. steel
3- KEVLAR® is not susceptible to corrosion in a high moisture environment
4- On high speed applications, KEVLAR® will not generate any electrical interference. 

Why use a polyurethane timing belt vs. other types of timing belts?
Polyurethanes have unsurpassed abrasion resistance contrary to other plastics. Polyurethane will not abrade particles which can contaminate critical components in your drive, your product or your environment.

Relatively hard polyurethanes still maintain good flexibility without the use of a plasticizer. This equates to a stiffer overall system versus using a rubber belt such as neoprene. Polyurethanes can maintain this flexibility over a significant temperature range (-30°C to 80°C with short term to 120°C). Polyurethane also does not harden and degrade with age to the degree that neoprene does. Polyurethanes are highly elastic and tough which helps them to absorb shock and impact. 

What kind of chemical environment can urethane belts be used in?
Polyurethanes are generally resistant to ozone, hydrocarbons, fats, oils, room temperature water. They are generally attacked by concentrated acids, ketones, esters, chlorinated compounds, nitro hydrocarbons and high temperature water. We cannot control the environment under which a belt is used, it is up to the customer to ultimately determine the appropriateness of the belt under their exact conditions.

Why use nylon on the tooth or back side of the belt?
Neoprene belts use a nylon fabric on the tooth side of the belt in order to increase the shear strength of the neoprene tooth and to enhance the abrasion resistance. 

The use of Nylon on the teeth of a polyurethane belt to reduce the coefficient of friction and the noise that can occur between the belt and the pulley for high speed uses.

Nylon on the back is used on a urethane belt to reduce the coefficient of friction accumulation applications where product must slide on the back of the belt or for other applications where low friction is desirable on the back of the belt.